Fan



.'Au .11,1931. E. E. CAMPBELL; 1,818,607

FAN

Fiied Aug.- 27. 1928 INVENTOR ELBA ,E. CAMPBELL.

Patented Aug. 11, 1931 "UNITED STATES ELBA E. CAMPBELL, or DETROIT,

MICHIGAN, ASSIGNORJIO CHRYSLER CORPORATION,

OF DETROIT, MICHIGAN, A CORPORATION OF DELAWARE FAN Application filed. August 27, 1928. 'SerialNo. 302,215.

This invention relates to a fan and more particularly to the formation of the fan blades. 7

In the manufacture of fans particularly fans of the type commonly used for cooling the engine of an automobile it is desirable to obtain a light inexpensive fan preferably formed from a stamping or stampings secured together. Heretofore when stamped 1 sheet metal fan blades have been used the leading edge of the blade causes a noise as it strikes the air and when the blades are provided with a slight camber the rear edge of the blade also causes a noise. 15 It is an important ob'ect of this invention to bend the edges the fan blades at an angle to the plane of the blades so that the edges do not strike the air to cause a noise.

Other objects and advantages of the in vention will more fully appear from the following description taken in connection with the accompanying drawings, in which:

Fig. 1 is a plan view of the fan.

Fig. 2 is a sectional view through one of the blades taken on line 2-2 of Fig. 1.

Referring to the drawings, I have shown a fan which, in the form illustrated, comprises two sheet metal stampings 12 and 14 riveted together as at 16 forming four blades U 18. Each blade is bent at an angle to the plane of a central fiat portion 20 which forms the hub of the fan. Openings 22 have been provided to receive screws for atdriving the fan in a direction indicated by the arrow at the top of Fig. 1.

Referring to Fig. 2, the angle of the blades 18, with respect to the flat hub portion 20, is illustrated by the blade shown in section and a slight camber is shown in the blade 21. The dotted lines 23, at the edges of the blade shown in section, illustrate the shape of the blade before it is bent. Heretofore common practice has been to provide fans either with flat blades or blades with a slight camber, the edges of which remain in the plane or contour of the blade.

By bending the edges of the blade out of :30 its plane new results have been obtained.

..- taching the fan to a rotatable member for' The forward or leading edge 24 of the blade is bent slightly upward out of the plane of the blade so that the edge 24 does not strike the air in a straight line but at an angle. In other words, the edge 24 is bent at an angle to the plane in which the fan rotates, hereinafter called the plane of the fan, greater than the angle of the blade with respect to'the plane of the fan. The rear or following edge 25 of each blade is bent slightly upward from the plane of the blade into the same plane as the plane of the fan. The result being that all whistling noises of the fan are eliminated.

The bent edges 24 and 25 not only eliminate the objectionable noise of the fan but stiffen it thereby decreasing vibration.

Having thus illustrated and described one embodiment of my invention it is to be understood that various changes including the size and degree of the angle of the bent edges may be made without departing from the spirit of my invention and it is not my intention to limit its scope other than by the terms of the appended claims.

What I claim is:

1. A fan having a plurality of blades each bent at an angle to the plane of the fan, the leading edge of each blade being bent at an angle to the plane of the fan greater than the angle between the plane of the blade and the plane of the fan, and the following edge. of each blade being bent at an angle to lie in the plane of the fan.

2. A fan having a plurality of blades each bent at an angle to the plane of the fan, one longitudinal edge of each blade being bent at an angle to the plane of the fan in the same direction of the blades and greater than the angle between the plane of the blade and the plane of the fan, and the other longitudinal edge of each blade being bent at an angle to'lie in the plane of the fan.

3. A fan having a plurality of blades each bent at an angle to the plane of the fan, each blade provided with a camber, the leading edge of each blade being bent at an angle to the plane of the fan greater than the angle between the plane of the blade and. the plane of the fan, and the following 100 edge of each blade being bent at an angle to lie in the plane of the fan.

4. A fan having a plurality of blades each bent at an angle to the plane of the fan, one longitudinal edge of each bladedbeing bent at an angle to the plane of the fan in the same direction as the blades and greater than the angle between the plane of the blade and the plane of the fan, and the other longitudinal edge of each blade being bent in the opposite direction of the blades and less than the angle between the plane of the blade and the plane of the fan.

5. A fan having a plurality of blades, the major portion of each of which is bent at an angle to the plane of the fan, the longitudinal side edges of each blade being bent adjacent the outer portions thereof in the same direction out of the plane of the blade.

6. A fan having a plurality of blades bent at an angle to the plane of the fan and each provided with a camber, the longitudi- 1121 edges of each blade being bent in the same direction out of the plane of the blade.

ELBA E. CAMPBELL. 

